Applicant has long ago recognized the desirability of providing a superior line of motionless mixers, that is, mixing elements which do not rely upon any moving parts to create and enhance the mixing operation. For example, in Applicant's U.S. Pat. No. 4,034,965, an invention was disclosed in the form of a motionless mixer created from a plurality of self-nesting, abutting and axially overlapping elements fitted into a conduit. Such elements were found to be capable of not only mixing two or more unlike materials but also of redistributing a single material for thermal or other purposes. Such elements were shown to be capable of fitting into a conduit carrying fluids to be mixed and were shown to be inexpensive to fabricate. Regarding this latter issue, the elements could be punch pressed from flat sheets.
Referring to FIG. 1, Applicant's previously disclosed element 6 includes a central flat portion 10, the plane of which is intended to be generally aligned with the longitudinal axis of the conduit in which it is placed. First and second ears 12 and 14 are rounded or otherwise configured at their outside peripheries for general fit to the wall of the conduit being bent upwardly and downwardly from the flat portion 10. A second pair of ears 16 and 18 at the opposite side of flat portion 10 was shown to be bent upwardly and downwardly, respectively. The angle between various sets of ears was taught to be preferably in the range of about 30 to 120 degrees and were preferably dimensioned to “spring” against the conduit wall so that a good fit is made to the wall without any need for brazing, gluing or otherwise permanently fixing each element to the conduit wall. Various elements were taught to stack or “nest” with respect to one another such that material moving longitudinally within a conduit experiences a counter-clockwise velocity vector or rotational vector imposed by ears 16 and 18 of element 6. The flat portion 10 transforms the rotational vector to a lateral or radial vector. Subsequent to the flat portion 10, ears 12 and 14 impose a further counter-clockwise velocity vector adding somewhat to the lateral or radial vector. It was also noted that ears 16 and 18 impose substantially inward directed radial velocity vector on materials moving longitudinally, where as ears 12 and 14 impose substantially outward directed radial velocity vector. Such devices have been employed for mixing and distributing all types of materials including liquids, solids, gases, foams, etc. Because various “nested” elements were not permanently fastened to each other or to the inner wall of the conduit, the conduit could be a flexible material so that the apparatus could take various curve shapes as may be required in particular applications.
Even though the material distributing and mixing apparatus as disclosed in Applicant's previous U.S. Pat. No. 4,034,965 represented a breakthrough in material distribution and mixing, certain drawbacks were recognized in the use of such apparatus which have been now made the subject of the present invention. For example, it has been recognized that after fluids impacting upon element 6 are acted upon by this mixing element, it can, in some instances, engage in violent rotation causing centrifuging also known as “barber poling.” Additionaly, because of the perceived need to properly place mixing elements within a conduit both as individual and “nested” elements, it was believed necessary that mixing apparatus including such elements and supporting conduit would require factory fabrication which, in turn, required shipping of such mixing apparatus as the combination of mixing elements themselves and conduit as a single unit. This obviously added to shipping costs as conduit which could have been provided by an end user on site had to be shipped together with the appropriate mixing elements.
It is thus an object of the present invention to provide a material distributing and mixing apparatus which is improved over prior apparatus by eliminating the limitations are recited above.
These and further objects will be more readily apparent when considering the following disclosure and appended claims.